By combining results from the MARK-J at PETRA on Bhabha scattering, μ + μ - and τ + τ - production with recent world data from neutrino-electron scattering experiments, we determine unique values for the leptonic weak neutral current coupling constants g V and g A in the framework of electroweak models containing a single Z 0 . In contrast to previous analyses, we only use data from purely leptonic interactions, and therefore avoid the inherent uncertainties resulting from the use of hadronic targets. From the MARK-J data alone in the context of the standard SU(2) ⊗ U (1) model of Glashow, Weinberg and Salam, we find sin 2 θ W =0.24±0.11.
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The first measurements are reported of the asymmetry in resonance-region scattering of longitudinally polarized electrons by longitudinally polarized protons. Data have been obtained at Q2=0.5 and 1.5 (GeV/c)2 in the missing-mass range W=1.1−1.9 GeV. Results are compatible with a multipole analysis of single-pion electroproduction. The spin-dependent behavior is consistent with a duality mechanism as in the unpolarized case.
ELECTRON ASYMMETRY AT Q**2 ABOUT 0.5 GEV**2.
ELECTRON ASYMMETRY AT Q**2 ABOUT 1.5 GEV**2.
PHOTON ASYMMETRY AT Q**2 ABOUT 0.5 GEV**2.
We have observed high mass resonances with mass above 1.5 GeV in pp interactions at 405 GeV/ c . We obtain cross sections 13.2 ± 2.9, 5.1 ± 2.0, 2.5 ± 1.5 and 0.27 ± 0.18 mb for ϱ 0 , f, g 0 , and h meson production, respectively. The invariant x and p T 2 distributions for produced resonances are analysed. A relative comparison of the average 〈 p T 〉 distribution as a function of resonance masses with that for μ + μ − pair production shows remarkable similarity.
ONLY INCLUSIVE CROSS SECTIONS ARE GIVEN IN THE ORIGINAL PAPER. MULTIPLICITY VALUES ARE OBTAINED BY DIVIDING THE CORRESPONDING CROSS SECTION BY INELASTIC P P 32.0+-1.0 MB ONE ACCORDING TO PR D20, 37.
Production of pions, kaons, protons and antiprotons has been studied in e + e − annihilations at 12 and 30 GeV centre of mass energy using time of flight techniques. The fractional yield of charged kaons and baryons appears to rise with outgoing particle momentum. At our highest energy at least 40% of e + e − annihilations into hadrons are estimated to contain baryons.
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The spin dependence of π 0 inclusive production by 24 GeV/ c protons has been measured using a polarized target for Fhe Feynman x near 0 in the transverse momentum range 1.0 < p T < 2.5 GeV/ c . The results indicate a negative updown asymmetry growing strongly with p T and greater than 50% in absolute value for p T greater than 2 GeV/ c .
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In this Letter, a measurement of inclusive muon production (pμ>2 GeV/c) in e+e− annihilation into hadrons at center-of-mass energies from s=12 to 31.6 GeV is reported. The results agree with the expected semileptonic decays from charmed and bottom mesons.
MUONS PER HADRONIC EVENT.
INVARIANT CROSS SECTION, ASSUMING HADRONIC CROSS SECTION HAS R VALUE OF 3.9 +- 0.5.
During an energy scan at the Cornell Electron Storage Ring, with use of the Columbia University-Stony Brook NaI detector, an enhancement in σ(e+e−→hadrons) is observed at center-of-mass energy ∼10.55 GeV. The mass and leptonic width of this state (ϒ′′′) suggest that it is the 4S13 bound state of the b quark and its antiquark. After applying to the data a cut in a (pseudo) thrust variable, the natural width is measured to be Γ=12.6±6.0 MeV, indicating that the ϒ′′′ is above the threshold for BB¯ production.
VISIBLE TOTAL HADRONIC CROSS SECTION FOR FIRST, THIRD AND FOURTH UPSILONS.
The average transverse momentum squared, 〈 p ⊥ 2 〉, of hadrons is studied as a function of W 2 and of Q 2 for ν and ν interactions on an isoscalar target. An increase of 〈 p ⊥ 2 〉 with W 2 is observed for the hadrons emitted forward in the hadronic c.m.s. The p ⊥ dependence of the fragmentation function is found to factorise from the structure function at fixed W , but does not factorise at fixed Q 2 . Unlike the case of forward-going particles, the 〈 p ⊥ 2 〉 of hadrons going backward in the c.m.s. shows no strong dependence on W 2 .
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A study of the reaction π − p → X − p based on 1.27 × 10 6 events, corresponding to a mean sensitivity of 200 events/μb, is presented. Properties of the exclusive channels π − p → π − π 0 p, π + π − π − p, π + π − π − π 0 p, π + π + π − π − π − p and π + π + π − π − π − π 0 p are discussed.
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Inclusive K 0 -production has been measured in e + e - annihilation at a center of mass energy of about W = 30 GeV. The ratio of K 0 + K 0 production to μ + μ - production is R K 0 = 5.6 ± 1.1 (statist. error) ± 0.8 (system.error) This value is about a factor of three higher than R K 0 at W = 7 GeV. The cross sections ( s / β ) d σ /d x is consistent with a scaling behaviour.
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DIFFERENTIAL CROSS SECTION.
INVARIANT CROSS SECTION.
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